In spite of many inventions related to marking, current marking techniques still cannot be used in many applications. One of these applications is high efficiency, minimally invasive marking of biomaterials, like DNA and proteins, but not only limited to them. DNA absorption rates of lowest excited state (LES) and higher excited states (HES) are very small, which means that high intensity UV light is needed to excite DNA to LES and then high intensity UV-VIS-NIR light to excite DNA from LES to HES. The high intensity UV light not only excites DNA but also generates photoproducts from photolysis of water and photodamaging of other molecules. These photoproducts are very reactive chemical species which can interact with DNA, proteins, and other biomolecules causing their substantial damage and are carcinogenic to the body. The damaged biomolecules cannot be used for further biomaterial production and research. Another example of the great need for minimally invasive marking is writing on very fragile materials, like thin foils used, for example, as packaging materials. Current optical, electrical, thermal, or other marking techniques can potentially damage thin foils. Clear writing on thin foils without damaging foils is difficult to achieve, because the energy thresholds of the writing effect and the damaging foil are very similar. Therefore, exists the great need for techniques that will provide lower energy thresholds for writing, e.g. enhanced efficiency of the marking effect, and higher energy thresholds for damaging foils.
Marking with high spatial and three-dimensional resolutions is also needed, particularly in memory devices, like hard drives, CD disks, and electronic printed boards, but not limited to them. Therefore, there is a great need for marking techniques with inherent subwavelength, atomic or molecular resolutions and for techniques enabling three-dimensional writing in materials.
The invention described here fulfills the above mentioned current great needs in marking techniques and can be also used in other marking applications.